Initial light rendering code, doesn't render correct in all situations yet.

code/redalert/light.cpp

@@ -30,9 +30,29 @@ LightManager::LightManager() {
 void LightManager::Init(void) {
 	lightEditorIcon = Image_LoadImage("ui/edwin/lightbulb.png");
 	pointLightAttenImage0 = Image_LoadImage("ui/lights/light_point_atten.png");
+
+	hdrLightBufferTexture = Image_CreateBlankImage("hdrRenderTexture", ScreenWidth, ScreenHeight);
+	hdrRenderTexture = new RenderTexture(hdrLightBufferTexture, NULL);
+	hdrRenderTexture->InitRenderTexture();
 }
 
 void LightManager::RenderLights(void) {
+	if(Debug_Map) {
+		for (int i = 0; i < MAX_WORLD_LIGHTS; i++) {
+			if (!lights[i].active) {
+				continue;
+			}
+
+			if (!lights[i].isPending) {
+				int screenx, screeny;
+				lights[i].GetRenderPosition(screenx, screeny);
+				GL_RenderImage(lightEditorIcon, screenx, screeny, 30, 30);
+			}
+		}
+	}
+
+	GL_SetRenderTexture(hdrRenderTexture);
+
 	for (int i = 0; i < MAX_WORLD_LIGHTS; i++) {
 		if (!lights[i].active) {
 			continue;
@@ -41,9 +61,16 @@ void LightManager::RenderLights(void) {
 		if (!lights[i].isPending) {
 			int screenx, screeny;
 			lights[i].GetRenderPosition(screenx, screeny);
-			GL_RenderImage(lightEditorIcon, screenx, screeny, 30, 30);
+			int halfRadius = lights[i].radius / 2;
+			GL_RenderImage(pointLightAttenImage0, screenx - halfRadius, ScreenHeight - (screeny + halfRadius), lights[i].radius, lights[i].radius);
 		}
 	}
+
+	GL_SetRenderTexture(NULL);
+
+	GL_EnableBlend(GL_BLEND_MULT);
+		GL_RenderImage(hdrLightBufferTexture, 0, 0, ScreenWidth, ScreenHeight);
+	GL_EnableBlend(GL_BLEND_NONE);
 }
 
 void LightManager::FreeAllLights(void) {
@@ -76,12 +103,12 @@ Light_t *LightManager::PlaceLight(char *name, int x, int y, float r, float g, fl
 	else {
 		strcpy(light->name, name);
 	}
+	light->position = XYP_Coord(x, y);
 	light->color.x = r;
 	light->color.y = g;
 	light->color.z = b;
 	light->radius = radius;
-	light->type = type;
-	light->PlaceLight(x, y);
+	light->type = type;	
 
 	return light;
 }

code/redalert/light.h

@@ -5,6 +5,7 @@
 #include "vectormath.h"
 
 class CCINIClass;
+class RenderTexture;
 struct Image_t;
 
 #define MAX_WORLD_LIGHTS			6556
@@ -55,6 +56,9 @@ private:
 	int							numLights;
 	Image_t*					lightEditorIcon;
 	Image_t*					pointLightAttenImage0;
+
+	Image_t*					hdrLightBufferTexture;
+	RenderTexture*				hdrRenderTexture;
 };
 
 extern LightManager lightManager;

code/redalert/mapedit.cpp

@@ -1682,7 +1682,7 @@ void MapEditClass::Main_Menu(void)
 				break;
 
 			case 8:
-				GrabbedLight = lightManager.PlaceLight(NULL, 0, 0, 1.0f, 1.0f, 1.0f, 100, LIGHT_POINT);
+				GrabbedLight = lightManager.PlaceLight(NULL, 0, 0, 1.0f, 1.0f, 1.0f, 75, LIGHT_POINT);
 				GrabbedLight->isPending = true;
 				break;
 

code/redalert/newblit.cpp

@@ -4,6 +4,7 @@
 #include <imgui.h>
 #include "FUNCTION.H"
 #include "Image.h"
+#include "gl/glew.h"
 
 extern byte backbuffer_palette[768];
 extern uint8_t g_ColorXlat[16];
@@ -11,9 +12,38 @@ extern uint8_t g_ColorXlat[16];
 bool forceForgegroundRender = false;
 int32_t g_currentColor;
 
-//void GL_SetRenderTarget(void *renderTarget) {
-//	//ImGui::GetBackgroundDrawList()->AddCallback()
-//}
+static void GL_SetRenderTextureCallback(const ImDrawList* parent_list, const ImDrawCmd* cmd) {
+	RenderTexture* renderTexture = (RenderTexture*)cmd->UserCallbackData;
+	if(renderTexture == NULL) {
+		RenderTexture::BindNull();
+	}
+	else {
+		renderTexture->MakeCurrent();
+		glClearColor(0.5, 0.5, 0.5, 1.0);
+		glClear(GL_COLOR_BUFFER_BIT);
+	}
+}
+
+static void GL_EnableBlendCallback(const ImDrawList* parent_list, const ImDrawCmd* cmd) {
+	GLBlendType blendType = (GLBlendType)(int64_t)cmd->UserCallbackData;
+	glEnable(GL_BLEND);
+	if(blendType == GL_BLEND_NONE) {		
+		glBlendEquation(GL_FUNC_ADD);
+		glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+	}
+	else {
+		glBlendEquation(GL_ADD);
+		glBlendFunc(GL_DST_COLOR, GL_SRC_COLOR);
+	}
+}
+
+void GL_EnableBlend(GLBlendType blendType) {
+	ImGui::GetBackgroundDrawList()->AddCallback(GL_EnableBlendCallback, (void *)blendType);
+}
+
+void GL_SetRenderTexture(RenderTexture *renderTexture) {
+	ImGui::GetBackgroundDrawList()->AddCallback(GL_SetRenderTextureCallback, renderTexture);
+}
 
 void GL_ForceForegroundRender(bool force) {
 	forceForgegroundRender = force;

code/redalert/newblit.h

@@ -2,6 +2,13 @@
 //
 
 struct Image_t;
+class RenderTexture;
+
+enum GLBlendType {
+	GL_BLEND_NONE = 0,
+	GL_BLEND_MULT
+};
+
 void GL_RenderImage(Image_t* image, int x, int y, int width, int height, int colorRemap = 0, int shapeId = 0);
 void GL_RenderForeGroundImage(Image_t* image, int x, int y, int width, int height, int colorRemap = 0, int shapeId = 0);
 void GL_DrawText(int color, int x, int y, char* text);
@@ -12,4 +19,6 @@ void GL_ResetClipRect(void);
 void GL_SetClipRect(int x, int y, int width, int height);
 void GL_ForceForegroundRender(bool force);
 void GL_DrawForegroundText(int color, int x, int y, char* text);
-void GL_SetColor(float r, float g, float b);
+void GL_SetColor(float r, float g, float b);
+void GL_SetRenderTexture(RenderTexture* renderTexture);
+void GL_EnableBlend(GLBlendType blendType);